WO2014111650A1

WO2014111650A1 - System and method for detecting the position of an actuation member on a display screen

Info

Publication number: WO2014111650A1
Application number: PCT/FR2014/050067
Authority: WO
Inventors: Jérôme VAILLANT
Original assignee: Commissariat A L'energie Atomique Et Aux Energies Alternatives; Isorg
Priority date: 2013-01-15
Filing date: 2014-01-14
Publication date: 2014-07-24
Also published as: FR3001064A1; EP2946273B1; JP2016503932A; US20150355784A1; KR102189041B1; EP2946273A1; FR3001064B1; JP6367234B2; KR20150129663A; US9965070B2

Abstract

The invention relates to a method comprising the following steps: displaying first successive images on a screen; acquiring at least one second image; searching for the position of at least one actuation member with respect to the screen on the basis of an analysis of the second image; and modifying at least one of the next first images to be displayed if conditions of determination of the position of the actuation member in the second image are only partially fulfilled.

Description

SYSTEM AND METHOD FOR DETECTING THE POSITION OF AN ACTING MEMBER ON A DISPLAY SCREEN

The present patent application claims the priority of the French patent application FR13 / 50350 which will be considered as an integral part of the present description.

Field

The present application relates to a device and a method for detecting the position of an actuator on a display screen.

Presentation of the prior art

There are user interface systems comprising a display screen and a device for detecting the position of an actuator, for example a stylus, a finger or the hand of a user on the screen. display. The sensing device may include a touch sensitive surface, or touch surface, which may be superimposed on the display screen. The user interface system is usually called a touch screen.

Touch screens are currently used in many areas. For example, they have already been used to control mobile phones, computers, television sets, motor vehicles, Automatic teries, industrial equipment, medical team ^¬ ments, etc.

Patent application WO 2011/119483 describes an example of user interface system comprising an Affi drying screen and a detection of an actuation member device including light emitting diodes and photodétec ^¬ tors disposed on the edges of the screen so as to detect the presence of the actuating member.

The publication entitled "Active Matrix LCD with Integrated Optical Touch Screen" in the names of W. den Boer, A. Abileah, P. Green, T. Larsson, S. Robinson and T. Nguyen (SID 03 DIGEST) describes a screen of LCD that incorporates optical sensors that are used to detect the shadow of an actuator on the screen.

summary

Thus, an embodiment provides a method comprising the following steps:

display first successive images on a screen;

acquire at least a second image;

searching for the position of at least one actuator relative to the screen from an analysis of the second image; and

modifying at least one of the next first images to be displayed if conditions for determining the position of the actuating member in the second image are only partially fulfilled.

According to one embodiment, the second image corresponds to the image of the light arriving on the screen.

According to one embodiment, the intensity of at least some pixels of the next first image to be displayed is increased or decreased.

According to one embodiment, only part of the next first image to be displayed is modified. According to one embodiment, the second image is a color image comprising at least two sub-images associated with distinct colors.

According to one embodiment, the position of the actuator relative to the screen is sought from the detection of the reflection of the first image by the actuator in each subimage.

According to one embodiment, the method comprises searching in each subimage of at least a first given pattern representative of the reflection of the first image by the actuating member.

According to one embodiment, the conditions for determining the position of the actuating member with respect to the screen are fulfilled if the reflection of the first image by the actuating member is detected at the same position in each subimage.

According to one embodiment, the conditions for determining the position of the actuating member with respect to the screen are only partially fulfilled if the reflection of the first image by the actuating member is detected in at least one embodiment. one of the sub-images and is not detected in all the sub-images.

According to one embodiment, the position of the actuator relative to the screen is sought from the detection of the shadow of the actuator in each subimage.

According to one embodiment, the method comprises searching in each subimage of at least a second given pattern representative of the shadow of the actuating member.

According to one embodiment, the conditions for determining the position of the actuating member with respect to the screen are fulfilled if the shadow of the action element ^¬ is detected at the same position in each sub. -picture.

According to one embodiment, the conditions for determining the position of the actuating member by ratio to the screen are only partially filled if the shadow of the actuator is detected in one of the subimages and is not detected in all the subimages.

An embodiment also provides a system comprising:

a display screen of first successive images; a device for acquiring at least a second image;

a device for finding the position of at least one actuator relative to the screen from an analysis of the second image; and

a device for modifying the next first image to be displayed if conditions for determining the position of the actuating member in the second image are only partially fulfilled.

According to one embodiment, the acqui ^¬ sition device comprises a matrix of photon sensors, the screen comprises a matrix of luminous display pixels and the matrix of photon sensors covers the screen or is integrated in the matrix. display pixels.

Brief description of the drawings

These and other objects, features, and advantages will be set forth in detail in the following description of particular embodiments in a non-limitative manner with reference to the accompanying figures in which:

FIG. 1 is a partial and schematic representation of an embodiment of a user interface system comprising a display screen and a device for detecting an actuator on the display screen;

Figure 2 illustrates, in the form of a block diagram, an embodiment of a method of detecting an actuator on a display screen;

Figure 3 is a partial schematic sectional view of an embodiment of the display screen of the interface system of Figure 1; Figure 4 illustrates, in the form of a block diagram, a more detailed embodiment of a method of detecting an actuator on a display screen;

FIG. 5 is a partial and diagrammatic section of an embodiment of the device for detecting the actuating member of the interface system of FIG. 1;

Figure 6 is a front view, partial and schematic, of the detection device of Figure 5; and

FIG. 7 is a partial schematic representation of an embodiment of the detection module of the interface system of FIG. 1.

detailed description

For the sake of clarity, the same elements have been designated by the same references in the various figures and, in addition, the various figures are not drawn to scale. In addition, only the elements useful for understanding the embodiments have been shown and are described. In particular, the use of the user interface systems described below has not been detailed. Those skilled in the art can use the proposed interface systems in any type of device that can be controlled via an interface with and / or without contact. In addition, the information processing means provided by the user interface systems described below, and the means of connection with the device or devices to be controlled, are within the reach of those skilled in the art and are not not described. In the rest of the description, unless otherwise indicated, the terms "substantially", "about" and "of the order of" mean "to within 10%".

In the patent application WO 2011/119483, the presence of the light-emitting diodes and photodetectors at the periphery of the display screen increases the bulk of the user interface system. In particular, the thickness of the interface system must be sufficient to house the light-emitting diodes and the photodetectors at the periphery of the display screen. In addition, the efficiency of detection can be reduced in the case of strong ambient lighting, for example in the case where the sun's rays directly hit the display screen.

In the publication by W. den Boer et al., The detection of the actuator on the display screen is obtained from the detection of the shadow of the actuator on the screen display. Detection efficiency can be reduced in the event of low or no ambient lighting or in the event of large variations in ambient lighting.

It would be desirable to have a method of detecting, by a user interface system, the position of an actuator on a display screen whose reliability is improved, particularly in case of high illumination and in case of low illumination.

Thus, an object of an embodiment is to provide a method of detection, by a user interface system, of the position of an actuator on a display screen at least partially overcoming some of the disadvantages existing processes.

Another object of an embodiment is that the detection reliability of the actuator is improved.

Another object of an embodiment is that the user interface system can be used in conditions of high illumination and low illumination.

Another object of an embodiment is that the user interface system includes an actuator position sensing device overlaying the display screen or integrated with the display screen.

Another object of an embodiment is that the position of the action member ^¬ ment detection device operates with or without contact of the action member ^¬ ment on the display screen.

Another object of an embodiment is that the detection method can be implemented with any type display screen, in particular a liquid crystal screen, a plasma screen or a screen based on organic semiconductor components, for example organic light-emitting diodes.

Another object of an embodiment is that the detection method can be implemented with any type of detection device based on photodetectors, in particular photodetectors made of inorganic or organic semiconductor materials.

FIG. 1 represents an embodiment of a user interface system 1 comprising an emissive display screen 5 and a device 6 for detection with or without contact of an actuating member 7. The actuating member 7 may correspond to a stylus, a finger or the hand of a user.

A pixel of an image corresponds to the unitary element of the image displayed by the screen 5. When the screen 5 is a color image display screen, the display screen 5 generally comprises for the display of each pixel of the image at least three transmitting components and / or regulating the light intensity, also called sub-pixels of affi ^¬ drying, which each emit a light radiation substantially in a single color (for example, red, green and blue). The superposition of the radiation emitted by these three sub-display pixels provides the observer with the color sensation corresponding to the pixel of the displayed image. In this case, the display pixel of the display screen 5 is the set formed by the three display sub-pixels used for displaying a pixel of an image. When the screen 5 is a monochrome image display screen, the display screen 5 generally comprises a single light source for displaying each pixel of the image.

The display screen 5 comprises an array of display subpixels 8 (R, G, B), for example, divided into rows and columns. Two Pix Pixel Display Pixels, including each three sub-display pixels, are shown in Figure 1. A display screen 5 may comprise of the order of 300,000 to 200,000 pixels of display. Each sub-display pixel 8 comprises an electronic component adapted to emit a light signal and / or to regulate the intensity of the light signal passing through it and emitted by a light source that can be common to several sub-pixels. display pixels 8. The display screen 5 can be an LCD (Liquid Crystal Display), a plasma screen or a screen based on organic semiconductor components. By way of example, in the case of an LCD screen, each sub-display pixel 8 may comprise liquid crystals adapted to more or less let the light beam coming from a light source that may be common to several sub-pixels of display.

The detection device 6 comprises a matrix of photon sensors 9 (Ph) or photodetectors, for example distributed in rows and columns. For example, only six photodetectors 9 are shown in Figure 1. A photograph ^¬ detector 9 is an electronic component adapted to provide an electrical signal which depends on the amount of light received by the photodetector 9. The photodetector 9 may include photodiodes, photoresistors, phototransistors, etc. The number of photodetectors 9 may be less than or equal to the number of sub-display pixels 8. Preferably, the number of photodetectors 9 is equal to the number of sub-display pixels 8.

In FIG. 1, the display screen 5 and the detection device 6 are shown separately for the sake of clarity. However, the photodetector 9 matrix can be achieved integrally with the display sub-pixel matrix 8. Alternatively, the photo detectors ^¬ matrix 9 may overlap the display sub-pixel matrix 8. The photodetectors 9 are protected so as not to receive directly the light emitted by the display screen and to receive only the light due to ambient lighting, that is to say that is, the light flow that reaches the display screen 5 from outside the display screen 5.

The system 1 comprises a control module affi ^¬ chage 10 (Display Command) connected to the display screen 5 by a module 11 for selecting display subpixels 8. The display control module 10 comprises, for example, a memory in which a digital image can be stored. By digital image is meant the digital representation of an image. Preferably, the digital image comprises an array of numerical values that depend on the type of color coding used. The control module 10 provides the display screen 5 with control signals adapted to obtain the display on the display screen of an image corresponding to the stored digital image. For example, in the case of an LCD screen, the module 10 is adapted to control the display of an image on the screen 5 by selecting the liquid crystals 9 blocking the passage of light or letting pass the light.

The system 1 comprises a module 12 (detection unit) for detecting the actuator 7 connected to the photodetector array 9 by a photodetector selection module 9. The selection modules 11 and 13 may be at least common part. The module 12 comprises, for example, a memory in which can be stored a digital image obtained from the signals provided by the photodetectors 9.

According to one embodiment, the system 1 is produced using a conventional display screen 5 to which the detection device 6 is added. The photodetector matrix 9 then covers the matrix of sub-display pixels 8.

According to another embodiment, the structure of a conventional display screen can be modified to produce the photodetectors 9 directly at the display sub-pixels 8 of the display screen 5. By way of example when the display screen 5 corresponds to a liquid crystal display, the detection device 6 may comprise photodetectors 9 as described in US patent application 2010/0013793. When the display screen comprises organic light-emitting diodes, the detection device 6 may comprise photodetectors 9 made from organic semiconductor materials as described in the French patent application FR11 / 58607.

An embodiment will be described in more detail in the case of a color LCD. However, it is clear that the display screen could be of another type, for example a plasma screen or a screen based on organic semiconductor components, for example organic electroluminescent diodes.

FIG. 2 represents, in the form of a schematic block, an embodiment of a method for detecting an interaction between an actuating member and a user interface system that can notably be implemented with the user interface system 1 shown in FIG. 1. A detection of an interaction between the actuating member and the user interface system corresponds to the detection of the position of the actuating member on the screen display (contact detection) or near the display screen (contactless detection). At least the steps 20, 22, 24 described below can be implemented paral ^¬ the element in the display of successive images on the screen 5.

In step 20, a new digital image is acquired by the detection module 12 from the signals provided by the photodetectors 9. An image element is called an element of the matrix of an image. By way of example, the numerical value of an image pixel of the acquired image depends on the signal supplied by one of the photodetectors 9.

The acquisition frequency of a new digital image can be made at a rate of 5 or 10 Hertz. It may be lower than the display frequency of new images on the display screen 5. In addition, the acquisition frequency of new digital images may not be constant and vary according to the nature of the steps performed later in the implementation of this embodiment of the detection method, as will be described in more detail later. The process continues in step 22.

In step 22, the module 12 determines whether the actuating member is detected on the acquired digital image. In general, the presence of the actuating member is detected from an analysis of the signals supplied by the photodetectors 9. By way of example, a variation of the photodetector signals 9 due to the presence can be sought. of the actuator relative to the level of these signals in the absence of the actuating member. According to another example, a variation of photodetector signals 9 may be sought with respect to the signals of the last digital image acquired. The search can be performed for all the pixels of the acquired digital image or only for some of them. According to one embodiment, the module 12 determines conditions which must be satisfied for the actuating member to be definitely detected.

The result of an image analysis method for finding the actuating member can be:

a certain detection of the actuating member when all the detection conditions are fulfilled;

a certain absence of detection of the actuating member when no detection condition is fulfilled; or

an uncertainty as to the presence or absence of the actuator when the detection conditions are only partially fulfilled.

If, in step 22, the actuating member is detected, the method continues in step 24. If, in step 22, the actuating member is not detected, the method is continues in step 20 by acquiring a new digital image. Yes, in step 22, the detection of the actuator is uncertain, the process continues in step 26.

In step 24, the method continues with an action that depends on the detected position of the actuating member 7 with respect to the display screen 5. It can be any type of action according to the interface system considered. An example action may include displaying a menu, and so on. The process continues in step 20.

In step 26, the display module 10 modifies the next image displayed with respect to the image that should have been displayed to improve the reliability of the detection of the actuator by the research method implemented. in step 22, that is to say to end after the implementation of the search method in step 22 to a certain detection or a certain absence of detection.

The modification made to the image depends on the type of search algorithm used in step 22. A possibility of modifying the displayed image consists, for the next image displayed, or for the next images displayed, to increase or decrease. decrease the level of the image pixels of the displayed image, the entire image or only part of it. By way of example, the level of at least some display pixels of the next displayed image is increased or decreased by at least 0.5%, preferably by at least 1%, more preferably by at least 2%, especially at least 5%. Advantageously, the variation of the level of the image pixels is then not perceived or only slightly perceived by the observer. In another example, the level of at least some display pixels of the next displayed image is increased or decreased by at least CLU. at least 5 "6", preferably at least 10%, which advantageously makes it possible to increase the chances of detection of the actuator on the next image or images acquired. , the level of less than 50%, preferably less than 25%, more preferably less than 15%, even more preferably less than 10%, display pixels of the next displayed image are increased or decreased relative to the image pixels of the image that should have been displayed.

In order not to disturb the user's vision, the modification can be performed on a small number of successive displayed images or can be carried out intermittently. By way of example, the modification is maintained at most in 100, preferably in 50, more preferably in 25, even more preferably in 10, images and is, in any case, interrupted if a certain detection or a lack of certain detection takes place. According to one example, if a certain detection or a certain absence of detection is not determined when the total number of modified images to be displayed is reached, then the detection module 12 determines that there is certain absence of detection.

By way of example, when the modification of the displayed image is carried out intermittently, the modification is performed on an image displayed every two, three or four images. According to one example, when the modification of the displayed image is carried out intermittently, a digital image is acquired only after the display of a modified image. According to another example, when the modification of the displayed image is carried out intermittently, images are acquired after the display of a modified image and after the display of an unmodified image. The image acquired after the display of an unmodified image can be subtracted from the acquired image after the display of a modified image, and the search for the actuator can be performed on the image as well obtained.

In addition, the increase or decrease of the image pixel values of the displayed image can be achieved progressively, for example by at least 1%, preferably by at least 2%, more preferably by at least 5%, even more preferably at least 10% each time a new modified image is displayed, as long as an uncertain detection is obtained and until a threshold is reached. The threshold corresponds, for example, to a total variation of the pixel level of the image relative to the image which should have been displayed by 50% or even 100%.

By way of example, if a certain detection or a certain absence of detection is not determined when the threshold is reached, then the detection module 12 determines that there is a certain absence of detection. In another example, when the threshold is reached, modified images may continue to be displayed without, however, providing for an additional variation in the level of the modified image pixels.

In addition, in the case of uncertain detection, the acquisition rate of the images can be temporarily increased until certain detection or the absence of certain detection. By way of example, the acquisition frequency of the images may be temporarily multiplied by at least 2, preferably at least 3, more preferably at least 5, even more preferably at least 10. For example, in the case where the image acquisition frequency in the case of a certain detection or the absence of detection is 5 to 10 Hz, the acquisition frequency of the images, in the case of an uncertain detection, may be temporarily increased to 50 to 100 Hz.

FIG. 3 shows an embodiment of the display screen 5 of the system 1 of FIG. 1 in the case of a color LCD screen. Two adjacent display subpixels 8 are shown in FIG. 1. By way of example, each display pixel may be square based, the side of which is typically of the order of 200 μm. By way of example, each display pixel comprises three rectangular-based display subpixels 8 whose sides are of the order of 50 μm and 200 μm with a spacing of 20 μm between the sub-pixels of FIG. display, this spacing serving lines and addressing transistors and their masking as described below. Each display subpixel 8 comprises a liquid crystal block 30 which extends substantially over the entire surface of the sub-display pixel 8. The liquid crystal matrix 30 defines two main faces 31, 32 substantially parallel and opposite. A backlighting device 33 is arranged on the side of the face 31. The backlighting device 33 may be common to all the sub-display pixels 8. For example, the backlighting device 33 may be common to all the sub-display pixels 8. illumination 33 may comprise fluorescent tubes or light-emitting diodes. By way of example, the backlighting device 33 emits a white light which passes more or less through each block 30 of liquid crystals as a function of the polarization of these crystals.

Electrodes 34 are disposed on the face 31 and electrodes 35 are disposed on the face 32. The electrodes 34, 35 are made of a transparent conductive material, for example indium oxide doped with tin or ITO (Indium Tin Oxide). For example, the electrodes 35 form a continuous layer of a conductive and transparent material covering the entire face 32 which may also be completed by lines or columns made of a non-transparent material but significantly less resistive than the conductive and transparent material (for example aluminum, silver or copper) deposited on the spaces between the sub-display pixels. Each block of liquid crystals 30 can be made more or less opaque to the light flow provided by the backlighting device 33 by the application of a voltage between the electrodes 34, 35 sandwiching the liquid crystal block 30. The electrodes 34, 35 are selected by the selection module 11 which comprises for each display subpixel 8 a selection block 36 disposed between the backlight device 33 and the liquid crystal block 30. Each selection block 36 may comprise one or more transistors.

Non-transparent portions 37 are disposed between the backlighting device 33 and the selection blocks 36. The selection blocks 36 therefore do not receive the light. transmitted by the backlighting device 33. Non-transparent portions 38 are disposed on the electrodes 35 substantially opposite each selection block 36. The selection blocks 36 therefore do not receive the light of the illumination ambient. The opaque portions 37, 38 are, for example, made of a metallic material.

The electrode 35 of each sub-display pixel 8 is covered with a portion 39 of a material adapted to filter the light waves passing through it as a function of the wavelength. Each portion 39 is, for example, made of a colored resin. The portions 39 are called color filters thereafter. By way of example, each color filter 39 covers the entire electrode 35 of the display subpixel 8 with the exception of the part of the electrode 35 covered by the opaque portion 38. Preferably, each filter Colored 39 is adapted to preferentially pass light waves in a wavelength range around a specific wavelength. By way of example, three color filters 39 associated with three different specific wavelengths can be used. Specific wavelengths may correspond to or be close to primary color wavelengths. The three primary colors are, for example, red, green and blue. The color filters 39 may be distributed over the matrix of sub-display pixels 8 in an alternation of the three colors according to the rows or the columns.

For each display sub-pixel 8, the photodetec ^¬ tor 9 is disposed on the face 31 and is shown schematically in Figure 3 by a block. By way of example, each photodetector 9 may be inscribed in a square having 20 μm on its side. By way of example, the photodetector 9 associated with a display subpixel 8 may be adjacent to the selection block 36 associated with an adjacent display subpixel 8. Advantageously, for an LCD screen, the photodetectors 9 can be made in the form of phototransistors. This embodiment has the advantage of not modifying the technology. used to make the address matrix of the LCD.

The opaque portions 37 are interposed between the backlighting device 33 and the photodetectors 9. The photodetectors 9 therefore do not receive the light emitted by the backlighting device 33. The opaque portions 38 are not located opposite each other. 9. For each display sub-pixel 8, the color filter 39 also extends vis-à-vis the photodetector 9 of the display subpixel 8. Each photodetector 9 thus receives the light coming from the photodetector 9. ambient lighting after filtering by the color filter 39 of the sub-display pixel 8.

FIG. 4 illustrates, in the form of a block diagram, a more detailed embodiment of a method for detecting an interaction between an actuating member and a user interface system that may notably be implemented implemented with the user interface system 1 shown in Figure 1 in the case where the display screen 5 is a color screen. Detection of an interaction between the actuator and the user interface system corresponds to the detection of the position of the actuator on the display screen (contact detection) or in the vicinity of the display screen (contactless detection).

In step 50, a new digital image is acquired by the detection module 12 as previously described for the step 20 of the method illustrated in FIG. 2. Preferably, each digital image can be divided into three sub-images. each sub-image being obtained from the signals provided by the photodetectors 9 of sub-display pixels 8 associated with one of the three specific wavelengths described above. In the remainder of the description, the image in a given color plane is called the sub-image associated with this color. By way of example, the three sub-images associated with the primary red, green and blue colors are considered. A color pixel is called an element of the matrix of a sub-image. By way of example, the numerical value of a color pixel depends on the signal supplied by one of the photodetectors 9. According to the distribution of the color filters 39, the sub-images may not have the same number of color pixels. . However, preferably, the sub-images have the same number of color pixels. The process continues in step 52.

The principle of the present embodiment of the detection method is based on the fact that the numerical value of each color pixel can be divided into a first component and a second component.

The first component is representative of the light flow of the ambient lighting which reaches the display screen 5. In the absence of an actuator disposed in contact with the display screen 5 or sufficiently close to the display screen 5, the acquired digital image depends only on the characteristics of the light sources of the ambient lighting. In particular, if the ambient lighting is fixed, the digital images acquired successively are substantially identical in the absence of the actuator. When the actuator is in contact with the display screen or near the display screen, the first component is, in addition, representative of the shadow due to the interposition of the organ operating between the light sources of the ambient illumination and the display screen 5.

The second component is representative of the reflection of the image displayed by the display screen 5. In the absence of an actuator, the reflection signal is extremely weak and drowns in the ambient light. Indeed, it can be considered that the display screen 5 acts as a light source whose light is scattered by the objects around the display screen 5 and can be detected by the photodetectors 9. In the presence of a actuating member which interacts with the display screen 5, with or without contact, the second component increases in the area where the actuating member It is close to the display screen 5 because of the reflection of the image displayed on the actuator. Further, the closer the actuating member is to the display screen, the closer the reflected image is to the image displayed at least locally in the area where the actuator is close to the display screen 5.

Steps 52 to 58 described below illustrate a more detailed embodiment of step 22 described above.

In step 52, the detection module 12 determines a modified digital image by calculating the difference between the acquired digital image and a reference digital image. The difference can be made pixel by color pixel for each color plane. According to one embodiment, the reference image corresponds to the digital image acquired in the absence of interaction between the actuating member and the display screen 5. The method continues at step 54 .

In step 54, the detection module 12 determines, for each color plane of the modified image, whether the values of the color pixels are substantially constant. If this is the case, this means that the acquired digital image is little different from the reference image and that there is therefore no interaction between the actuator and the screen of affi ^¬ drying 5. the method then continues at step 50 by acquiring a new digital image. The reference image can then correspond to the last acquired digital image or to the average, color pixel per pixel of color, of the last digital images acquired without interaction. If the levels of the color pixels are not constant, this means that the acquired digital image is different from the reference image. The process then continues at step 56.

In step 56, the detection module 12 checks whether there is an interaction between the actuator and the display screen 5 according to at least one search algorithm, in particular among the first or second algorithms of research described below, and preferably according to at least two search algorithms, in particular the first and second search algorithms described below.

The first search algorithm consists of looking for the reflection of a part of the image displayed on the actuating member in order to deduce an information representative of the position of the actuating member with respect to the screen. 5. Preferably, the first algorithm is implemented separately for each color plane. According to one embodiment, the detection module 12 searches, in each color plane, whether there is a local correlation between the acquired digital image and the digital image associated with the displayed image.

More precisely, according to one embodiment, the detection module 12 determines, in each color plane, a modified displayed image from the displayed digital image and a modified acquired image from the acquired digital image. Each color pixel of the modified displayed image corresponds to the value of that color pixel of the displayed digital image minus the average value of all the color pixels of the same color plane. Each color pixel of the modified acquired image corresponds to the value of this image pixel of the acquired digital image minus the average value of all the color pixels of the same color plane.

The detection module 12 can furthermore determine for each color plane a working image for which the numerical value of each color pixel is equal to the difference between the numerical value of the same color pixel of the displayed image. modified and the numerical value of the same color pixel of the modified acquired image. In the case of an interaction, the numerical values decrease locally in the area of the image where the interaction takes place.

The detection module 12 can search the working image for known patterns depending on the expected shape of the actuator. This allows, advantageously, to obtain a filtering of the detected actuator according to its shape and to avoid a false detection in the case where an object in contact with or near the display screen does not have the expected shape. By way of example, this makes it possible to avoid the detection of the palm of the user's hand when a detection of a finger or of several fingers of the user is expected. An exemplary method includes determining the correlation between the work image and the pattern for different positions of the pattern relative to the work image. For example, a detection occurs in the case where the correlation is greater than a given detection threshold. For example, a single interaction between the actuator and the screen can be sought. In this case, the position of the pattern relative to the working image for which the correlation between the working image and the pattern is maximum can be searched. In another example, several interactions between the actuator and the screen can be searched simultaneously. This is the case, for example, when the user can use multiple fingers to interact with the screen. In this case, the positions of the pattern with respect to the working image can be searched for where the correlation between the working image and the pattern reaches a local maximum or is greater than the detection threshold.

The detection module 12 can determine, from the position or positions of the pattern with respect to the working image for which the correlation is maximal, the detection position or the detection positions of the actuating member by report to the display screen 5.

By way of example, when the actuator has not yet been detected, the detection module 12 can determine the correlation between the working image and the pattern for all possible positions of the pattern with respect to the image. working image. When the actuating member has been detected, the detection module 12 can first determine the correlation between the working image and the pattern only for positions close to the last position of the pattern or the last positions of the pattern with respect to the working image for which the correlation has been maximum, possibly locally, or greater than the detection threshold. If no detection takes place, the search can be continued on the entire working image.

The second search algorithm consists of searching for the shadow of the actuator on the acquired digital image. Preferably, the second algorithm is implemented separately for each color plane. According to one embodiment, the detection module 12 searches, in each color plane, a local minimum of the values of the color pixels, for example according to a particular pattern, which is representative of the shadow of the actuating member . A detection, for example, occurs if the minimum is below a given threshold. The detection module 12 can determine, from the position of the minimum relative to the working image, the detection position of the actuating member with respect to the display screen 5. The process continues at step 58.

By way of example, when the actuator has not yet been detected, the detection module 12 can search for the local minimum over the entire acquired digital image. When the actuating member has been detected, the detection module 12 can first search for the local minimum only for positions of the acquired digital image close to the last detected position of the local minimum. If no detection takes place, the search can be continued on the entire acquired digital image.

In addition, when the actuating member has not yet been detected in a given color plane, the detection module can first search for the actuating member, by the implementation of the first or the second algorithm described above, at the position or positions at which it has been detected in another color plane. In step 58, the detection module 12 determines whether a certain detection, an uncertain detection or a lack of detection is obtained after the implementation of the first search algorithm, and possibly the second search algorithm. The detection module 12 can determine, for the first search algorithm, whether the action element ^¬ ment has been detected at the same position relative to the display screen for the three color planes. If this is the case, the detection of the actuating member is certain and the method continues in step 60. Similarly, for the second search algorithm, the detection module 12 can determine whether the shadow of the actuator on the display screen 5 is detected at the same location for the three color planes. If this is the case, the detection of the actuator is certain and the method continues in step 60. In the case where no reflection has been detected by the first search algorithm for any color plane or no shadow has been detected by the second search algorithm for any color plane, there is a certain absence of detection and the process continues in step 50. In the other cases, the detection is uncertain and the method is continues at step 62.

An example of uncertain detection occurs if, during the implementation of each algorithm, there is at least one color plane for which no detection has been obtained and at least one color plane for which detection has been detected. obtained. Another example of uncertain detection occurs if, during the implementation of the first and / or second algorithm, a detection has been obtained for the three color planes corresponding to different detection positions of the actuating member. relative to the display screen 5.

In step 60, the method continues with an action as a function of the detection position of the actuating member with respect to the display screen 5 as previously described for step 24 of the method shown in Figure 2. The process continues at step 50. In step 62, the display module 10 modifies the next displayed image with respect to the image that should have been displayed to improve the reliability of detection of the actuator as previously described for the first time. step 26 of the method illustrated in FIG.

In the case of an uncertain detection resulting from the implementation of the first detection algorithm, the absence of detection of the reflection of the image displayed in a color plane may be due to a low reflection for this color or to an ambient lighting that hides the reflection for this color. A possibility of modifying the displayed image then consists, for the next image displayed, or for the next images displayed, of increasing the level of the color pixels of the image displayed in the color plane where the detection is uncertain.

In the case of an uncertain detection resulting from the implementation of the second detection algorithm, the absence of detection of the shadow of the actuator in a color plane may be due to a compensation of 1 '. shadow by the reflection of the image displayed for that color. A possibility of modifying the displayed image then consists, for the next image displayed, or for the next images displayed, of reducing the values of the color pixels of the image in the color plane or in the color planes where the shadow is expected and has not been detected.

In the case of an uncertain detection resulting from the implementation of the first or the second detection algorithm, the level of color pixels in the color plane can be increased or decreased only locally, at the position or positions where the The actuator has been detected in the other color planes. In addition, the level of color pixels can also be increased in a color plane in which detection has been performed, in the entire color plane or only locally at the detection position. To avoid disturbing the user's vision, the modification can be performed on a reduced number of successive images or can be performed intermittently, for example every other image or three. In the latter case, the first search algorithm is implemented only when the displayed image is modified. In addition, the modification of the color pixel values can be performed for all the color pixels of the color plane or only for the color pixels of the part of the color plane where the shadow is expected. In addition, the increase or decrease of the color pixel values of the displayed image can be achieved progressively, for example by 5% each time a new image is displayed, as long as uncertain detection is obtained and until a threshold is reached. If a certain detection is not obtained when the threshold is reached, then the detection module 12 determines that there is no detection. In the case of uncertain detection, the acquisition rate of the images may be temporarily increased until certain detection or no detection is obtained so as to accelerate the determination of certain detection or detection. the lack of detection. More generally, in the case of detection, certain or uncertain, the acquisition frequency of the images can be temporarily increased until the end of the detection of the actuator. This makes it possible to detect the changes in the positions of the actuating member in a fluid and rapid manner without however stressing the detection module 12 excessively in the absence of detection.

According to one embodiment, in step 50, the acquired digital image can be used to determine the intensity of the ambient lighting. The intensity of the ambient lighting can be obtained by determining the luminance of the acquired digital image. When the acquired digital images are encoded in the RGB color space, the intensity of the ambient lighting can be obtained by performing a matrix transformation of the digital image acquired from the RGB color space to the XYZ space and using the value of the luminance Y. According to one embodiment, the brightness of the image displayed by the display screen 5 can be modified according to the average value of the luminance Y of the color pixels of the acquired digital image.

According to one embodiment, in step 50, the acquired digital image can be used to determine the general color of the ambient lighting. The general color of ambient lighting can be obtained by determining the overall color of the acquired digital image. When the acquired digital images are encoded in the RGB color space, the overall color of the ambient lighting can be obtained by performing a matrix transformation of the digital image acquired from the RGB color space to the HSV space and by using the hue value H. According to one embodiment, the brightness of the image displayed by the display screen 5 can be varied according to the average value of the hue H of the color pixels of the image acquired digital.

Brightness or color changes can be made globally or locally. Indeed, it is possible to make a local correction of the brightness or the color of the displayed image. For example, in the case where the sun hits only part of the display screen 5, the brightness of the displayed image can be increased locally only on this part.

Advantageously, the first search algorithm is not disturbed in case of low ambient lighting and the second search algorithm is not disturbed in case of strong ambient lighting. Advantageously, the detection reliability of the method according to the embodiment in which the first and second algorithms are implemented is thus improved.

FIG. 5 is a partial sectional and diagrammatic sectional view of an embodiment of photodetectors 9, which is particularly adapted to the case where the photodetectors are part of a detection device 70 attached to a display screen. In Figure 5, two photodetectors 72 are shown. The photodetectors 72 may be divided into rows and columns. In operation, each photodetector 72 partially overlaps a display subpixel 8 of the display screen 5.

The photodetectors 72 are formed on one side of a support 74 or transparent or translucent dielectric substrate, for example glass or plastic.

Each photodetector 72 comprises a stack comprising, in order from the support 74:

a color filter 75 filtering the light rays in a similar manner to the color filter of the display sub-pixel covered by the photodetector 72;

a transparent electrode 76, for example of transparent conductive oxide (TCO), for example tin-doped indium oxide or ITO (Indium Tin Oxide);

an electron injecting portion 78, for example a highly doped transparent organic semiconductor polymer or a transparent and conductive metal oxide, for example of the ZnO type;

a portion 80 of a mixture of organic semiconductor polymers, for example poly (3-hexylthiophene) or poly (3-hexylthiophene-2,5-diyl) (P-type semiconductor), known under the name P3HT, mixed with methyl [6,6] -phenyl-C6-butanoate (N type semiconductor), known as PCBM;

a portion 82 of a highly doped organic semiconductor polymer (hole-injecting layer), for example a polymer known under the name PEDOT: PSS, which is a mixture of poly (3,4) -ethylenedioxythiophene and sodium polystyrene sulphonate; and an electrode 84, for example made of aluminum or silver.

Laterally, the semiconductor regions 80 of the photodetectors 72 are separated from each other by a transparent dielectric material 86. In addition, a transparent protective coating 88 covers the upper face of the matrix (electrode side 84).

According to one variant, the color filters 75 are not present. In this case, each photodetector 72 is made with a spectral response adapted to the color to be detected. This can be achieved by adjusting the polymeric compounds used and the layer thicknesses constituting the photodetector 72.

In this example, the photodetectors 72 are intended to be illuminated by the ambient light through the transparent substrate 74, and through the transparent layers 76 and 78. The device 70 can cover the display screen 5 on the side of the coating 88, each photodetector 72 being placed above a black area of the screen 5 or being masked by metal tracks of a display subpixel of the screen 5 so as not to receive light directly from 1 screen 5.

The transparent electrodes 76 may have, in top view, the form of parallel strips. In this case, the opaque electrodes 84 may correspond to parallel bands, each band 84 being connected to all the photodetectors of the same row of the detection device 70, and the transparent strips 76 extend perpendicularly to the rows and are connected to photodetectors of different ranks. Alternatively, the electrodes 76 may be part of a plate of the conductive and transparent material in contact with all the photodetectors 72.

The photodetectors 72 of the detection device 70 may be made by printing techniques. The materials of layers 78 to 88 described above can be deposited in liquid form, for example in the form of inks conductive and semiconducting using inkjet printers. By materials in liquid form, here also means gel materials deposited by printing techniques. Annealing steps are optionally provided between the deposits of the different layers, but the annealing temperatures may not exceed 150 ° C, and the deposition and any annealing may be carried out at atmospheric pressure.

The production of organic semiconductor components by printing techniques is for example described in the article "CEA-LITEN S2S printing platform for Organic CMOS and Sensors Devices" by Jean-Yves Laurent et al, conference LOPE-C, June 2011, Frankfurt.

FIG. 6 is a schematic view from above of the detection device 70 describing in more detail the selection means of the photodetectors 72. FIG. 6 shows diagrammatically and partially two rows 90 each comprising three photodetectors 72. selection element 92 is associated with each photodetector 72. The selection element 92 may correspond to an organic transistor (English Organic Thin Film Transistor or OTFT). One of the source and drain terminals of the transistor 92 is connected to the electrode 84 of the photodetector 72 and the other one of the source and the drain is connected to a conductive track 94. The conductive track 94 can be connected all the selection elements 92 of a row 90. The track 94 may be of an opaque material, for example metal. The gate of each transistor 92 may be controlled by a signal transmitted by a track 96 of a conductive and transparent material extending in a direction perpendicular to the rows 90. The track 96 may be connected to the transistors 88 of different rows 90.

In the case where the detection device 70 covers a display screen 5, two adjacent rows 90 are spaced apart by a row 98 of a transparent material to allow passage to the flow of light from the display screen 5. Preferably, the rows 90 have a width less than the width of the rows 98 so as not to hinder the view of the display screen 5 by a user.

In the case where the detection device 70 is integrated in the display screen 5, the display subpixels 8 of the display screen 5 are made in each row 98.

According to another embodiment, whether in the case where the detection device is integrated in the display screen or covers it, the touch-sensitive display screen may comprise a lenticular network covering the detection device. 70. The lenticular network may correspond to the lenticular network described in the French patent application FR12 / 58546.

The lenticular array comprises, for example, contiguous cylindrical lenses which extend parallel to the rows 90 and 98. These may be plano-convex cylindrical lenses. The width of each lens is substantially equal to the sum of the widths of the row 90 and the row 98. The focal length of each lens is adjusted so that the row 90 is approximately at the secondary focus of the lens. The lenticular array is positioned with respect to the rows 90 and 98 so that a lens covers a row 98 across the entire width and at least a portion of the width of at least one row 90 of photodetectors.

Each lens deflects the light rays emitted through the row 98 or collected by the row 90 (which forms a dark area). The light rays from a row 98 are slightly deviated and their directions remain relatively close to the optical axis while the light rays reflected by a row 90 of photodetectors are deflected in a direction deviating greatly from the optical axis. As a result, a user perceives only the light rays coming from rows 98 of sub-display pixels and does not perceive the dark zone of rows 90 of photodetectors. The user does not see than the image broadcast by the display screen 5 and does not see the detection device 70.

Light rays, whose inclination relative to the display screen is large, tend to be deflected by the lenses and be received by the photodetectors of the available detection ^¬ operative part. The detection of the actuating member which is close to the lenticular network can be based on the detection of the presence or absence of these rays of light grazing. The operation of the detection device 70 is not disturbed by the presence of the lenticular array.

In the previously described embodiments, photodetectors 9 adapted to capture light waves from ambient lighting in a wavelength range which may be different from the wavelength range of interest, have been considered. example around a primary color. Colored filters are then placed between the light sources of the ambient lighting and the photodetectors to let only the light waves whose wavelengths are in the range of interest. However, each photodetector 9 may be designed to detect only light waves in the wavelength range of interest that may be different from one photodetector to another. In this case, the color filters may not be present.

In previously described embodiments, method steps may be performed using one or more computing devices. Embodiments are not limited to operation with a particular type of computing device.

FIG. 7 is a block diagram of a computing device 1000 that can be used to realize the detection module 12 and / or the display control module 10. The computing device 1000 can comprise one or more processors 1001. (Processor (s)) and one or more computer readable non-transit storage media (e.g., memory 1003 (Memory)). The memory 1003 can store, in a non-transitory computer readable storage means, computer program instructions which, when executed, implement the steps of the detection method described above. The processor or processors 1001 may be coupled to the memory 1003 and may execute these computer program instructions to cause these steps to occur.

The computing device 1000 may also comprise a network input / output interface 1005 (Network I / O Interface (s)) by which the computing device can communicate with other computing devices (for example, over a network). ), and may also include one or more user interfaces 1007 (User I / O Interface (s)), through which the computing device can provide an output signal to a user and receive an input signal from the user. The utili ^¬ sateur interfaces may include devices such as a keyboard, a mouse, a microphone, a display device (p. Ex. A monitor or touch screen), speakers, camera, and / or various other types of input / output device.

The embodiments described above can be implemented in several ways. By way of example, the embodiments may be implemented using a dedicated circuit, a software or a combination thereof. When implemented by software, the software code can be executed on any appropriate processor (for example, a microprocessor) or a set of processors, whether provided in a single computing device or distributed between several computing devices. It should be noted that any component or set of components that performs the process steps described above may be considered one or more controllers that control the steps described above. The controller or the controllers can be implemented in many ways, for example with a dedicated electronic circuit or with a general purpose circuit (For example, one or more processors) that is programmed using software or firmware to perform the process steps described above.

In this regard, it should be noted that an embodiment described herein comprises at least one computer readable storage medium (RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk ( DVD) or other optical disk carrier, magnetic cassette, magnetic tape, magnetic storage disk or other magnetic storage device, or other computer-readable non-transitory storage medium) encoded with a computer program (c) that is, several executable instructions) which, when executed on one or more processors, performs the steps of the embodiments described above. The computer readable medium can be transportable so that the program stored thereon can be loaded onto any computing device to implement aspects of the techniques described herein. In addition, it should be noted that the reference to a computer program which, when executed, performs one of the method steps described above, is not limited to an application program executing on a host computer. On the contrary, the terms computer program and software are used here in a general sense to refer to any type of computer code (eg, a software app ^¬ cation, firmware, microcode, or any other form 'computer instructions) that can be used to ^¬ grammer one or more processors to implement aspects of the methods described above.

Particular embodiments have been described.

Various variations and modifications will be apparent to those skilled in the art. In particular, although an embodiment has been described in which two search algorithms have been implemented, only the search algorithm for the reflection of the image displayed by the actuator can be implemented. .

Claims

A method comprising the steps of: displaying first successive images on a screen (5);

acquire at least a second image;

searching for the position of at least one actuating member (7) with respect to the screen from an analysis of the second image; and

The method of claim 1, wherein the second image corresponds to the image of the light arriving on the screen (5).

The method of claim 1 or 2, wherein the intensity of at least some pixels of the next first image to be displayed is increased or decreased.

4. Method according to any one of claims 1 to 3, wherein only a portion of the next first image to be displayed is modified.

The method of any one of claims 1 to 4, wherein the second image is a color image comprising at least two subimages associated with distinct colors.

6. Method according to claim 5, wherein the position of the actuating member (7) relative to the screen (5) is sought from the detection of the reflection of the first image by the body of actuation in each subimage.

7. The method of claim 6, comprising searching in each subimage of at least a first given pattern representative of the reflection of the first image by one actuating member (7).

The method according to claim 6 or 7, wherein the conditions for determining the position of the actuating member (7) with respect to the screen (5) are fulfilled if the reflection of the first image by the actuating member is detected at the same position in each subimage.

The method according to any one of claims 6 to 8, wherein the conditions for determining the position of the actuating member (7) with respect to the screen (5) are only partially filled if the reflection of the first image by the actuator (7) is detected in at least one of the subimages and is not detected in all the subimages.

10. Method according to any one of claims 5 to 9, wherein the position of the actuating member (7) relative to the screen (5) is sought from the detection of the shadow of the actuating member (7) in each subimage.

11. The method of claim 10, comprising searching in each subimage of at least a second given pattern representative of the shadow of the actuating member (7).

12. The method of claim 10 or 11, wherein the conditions for determining the position of the actuating member (7) relative to the screen (5) are met if the shadow of the body of Actuation is detected at the same position in each subpicture.

13. Process according to any one of the claims

10 to 12, wherein the conditions for determining the position of the actuating member (7) with respect to the screen (5) are only partially filled if the shadow of the actuating member (7) is detected in one of the subpictures and is not detected in all the subpictures.

14. System (1) comprising:

a screen (5) of the first display image ^¬ sive;

an acquisition device (9) of at least a second image; a device (12) for finding the position of at least one actuating member (7) with respect to the screen from an analysis of the second image; and

a device for modifying the next first image to be displayed if conditions for determining the position of the actuating member in the second image are only partially filled.

The system of claim 14, wherein the acquisition device (9) comprises a photon sensor array, wherein the screen (5) comprises an array of light display pixels (8) and wherein the photon sensor array overlays the screen or is integrated with the display pixel array.